Golf ball incorporating melt processable highly-crosslinked rubber-containing ionomer(s)

Abstract

Golf ball incorporating layer(s) of a mixture consisting of: i) ionomer(s); ii) ethylene propylene rubber(s)(EPR(s)); iii) polymeric epoxy crosslinker(s); and iv) compatibilizing polymer(s). The ionomer(s) and EPR(s) may be included in a blend in a wt % ratio of from about 85:15 to 55:45; the at least one polymeric epoxy crosslinker and compatibilizing polymer may be included in amounts, based on 100 parts of the blend, of from about 2.0 to about 10.0 parts; and from about 1.0 to about 10.0 parts, respectively. Each ionomer, EPR, polymeric epoxy crosslinker, and compatibilizing polymer has a density less than 1.0 g/cm3. The mixture is melt processable/moldable without meanwhile sacrificing target CoR, DCM compression, Shore D hardness, and Shore C hardness.

What is claimed is: 
     
       1. A golf ball comprising at least one layer consisting of a mixture of:
 i) at least one ionomer; ii) at least one ethylene propylene rubber; iii) at least one terpolymer of ethylene, acrylic ester and glycidyl methacrylate epoxy crosslinker; and iv) at least one anhydride modified high density polyethylene compatibilizing polymer; 
 wherein the mixture has a discontinuous phase that is dispersed throughout and contained within a continuous phase comprised of the ethylene propylene rubber; wherein the discontinuous phase is a cross-linked ionomer produced by a reaction between free epoxy groups of iii) and free carboxylic acid groups of the ionomer. 
 
     
     
       2. The golf ball of  claim 1 , wherein the at least one ionomer and the at least one ethylene propylene rubber are included in a blend in a wt % ratio of from about 85:15 to 55:45; and wherein iii) is included in the mixture in an amount of from about 2.0 to about 10.0 parts based on 100 parts of the blend; and wherein iv) is included in the mixture in an amount of from about 1.0 to about 10.0 parts based on 100 parts of the blend. 
     
     
       3. The golf ball of  claim 2 , wherein the at least one ionomer and the at least one ethylene propylene rubber are included in a blend in a wt % ratio of from about 65:35 to 70:30; and wherein iii) is included in the mixture in an amount of from about 3.0 to about 5.0 parts based on 100 parts of the blend; and wherein iv) is included in the mixture in an amount of from about 1.5 to about 2.5 parts based on 100 parts of the blend. 
     
     
       4. The golf ball of  claim 1 , wherein the at least one layer is an inner cover that is surrounded by an outer cover layer comprised of a thermoset polyurethane. 
     
     
       5. The golf ball of  claim 1 , wherein the at least one layer is an inner cover that is disposed about a spherical subassembly and is surrounded by an outer cover layer comprised of a thermoplastic polyurethane. 
     
     
       6. The golf ball of  claim 1 , wherein the at least one layer is an outer cover layer having a Shore D material hardness of from 45 to 65 and is formed about a spherical subassembly. 
     
     
       7. The golf ball of  claim 1 , wherein the at least one layer has a material hardness of from about 45 Shore D to about 65 Shore D and surrounds a core having a surface hardness of from about 70 Shore C to about 92 Shore C; and an outer cover layer has a material hardness of from about 40 Shore D to about 65 Shore D. 
     
     
       8. The golf ball of  claim 7 , wherein the core is a single core having a geometric center hardness that is less than or equal to the surface hardness of the single core. 
     
     
       9. The golf ball of  claim 7 , wherein the core comprises an inner core surrounded by an outer core layer. 
     
     
       10. The golf ball of  claim 1 , wherein the mixture has melt flow index that is no lower than 0.01 g/10 min@190° C./2.16 kg. 
     
     
       11. The golf ball of  claim 10 , wherein the mixture has a melt flow index (g/10 min@190° C./2.16 kg) that is at least half that of the mixture without iii). 
     
     
       12. The golf ball of  claim 10 , wherein the mixture has a melt flow index (g/10 min@190° C./2.16 kg) that is at least 1.5 time lower than that of the mixture without iii). 
     
     
       13. The golf ball of  claim 10 , wherein the mixture has a melt flow index (g/10 min@190° C./2.16 kg) that is at least 2.5 time lower than that of the mixture without iii). 
     
     
       14. The golf ball of  claim 10 , wherein the mixture has a melt flow index (g/10 min@190° C./2.16 kg) that is at least 3.5 time lower than that of the mixture without iii).